His point of view was significantly higher than he was used to. Looking down, he could see a blond man who began speaking to him with a haughty grin.
“Hm? You want to know why I don’t fear you...? Why even ask something so obvious? It’s because I am a sage who possesses wisdom that even surpasses that of the gods, of course.”
Most likely, these were the memories of the Servant he was supplying with magical energy — Alkeides.
Cool-headed observation told Bazdilot that the man was speaking some ancient language of the region around the Aegean Sea. Possibly due to the modern knowledge bestowed on the Heroic Spirit, or possibly due to his own influence through the pass that linked them, however, his brain registered it as the language he ordinarily used.

Fate/Strange Fake: Volume 4, Chapter 10 ("Day 2")